Soil microorganisms and animals represent as much as a quarter of the Earth’s described biodiversity. The very complex and diverse communities in which soil organisms interact can host millions of species and billions of individual organisms within a single ecosystem. Although our understanding of how soil biodiversity impacts the structure and functioning of terrestrial ecosystems is still incipient, significant progress has been made in recent years with a growing number of studies addressing key questions regarding the role of soil biodiversity in ecosystems globally. This session aims to present case studies that illustrate the recent progress made in this field of research, and to look at how the new technologies available to explore the ecological role of soil biota have helped to explain ecological patterns in diverse biomes in different regions of the world. This symposia will focus on studies investigating how soil biodiversity regulates plant community dynamics, above- and belowground trophic interactions, and biogeochemical cycles, and how these major frameworks have provided valuable insight into this unseen world. The symposia will showcase examples of current collaborations contributing to the Global Soil Biodiversity Initiative (GSBI), an international scientific effort. The GSBI is developing a coherent platform for promoting the translation of expert knowledge on soil biodiversity into environmental policy and sustainable land management for the protection and enhancement of ecosystem services.